The Chemical Composition of the Spinal Fluid

Abstract

Differential diagnosis between the various forms of meningeal or central nervous system disease has not become simpler as our knowledge of the pathology and chemistry of these conditions has increased. While it is relatively easy to diagnose clinically the acute inflammatory or purulent types of disease from those of a less acutely inflammatory nature, the differentiation between the diseases comprising each group is still clinically and chemically confused. The clinical picture of epidemic, pneumococcal, influenzal or streptococci meningitis is, as a rule, distinct from that of epidemic encephalitis, anterior poliomyelitis, polioencephalitis or tuberculous meningitis.Bacteriologically, the distinction in the former group is clearly enough defined. Chemically, the evidence is less definite in both groups. Differentiation between meningitis and meningismus, tetany and certain types of birth injuries at times may be very difficult. The determination of the primary lesion in instances of combined cardiorenal and meningeal conditions is often impossible, either clinically or with the aid of chemical investigation. A changed relation in the sugar concentration in blood and spinal fluid seemed at first to offer a differential point between poliomyelitis and encephalitis-two diseases often clinically confused.It must be recognized that it is the level of the cerebrospinal axis involved, not the type of condition, that determines this changed relation between blood and spinal fluid sugar.There is reason to believe that the permeability of the choroidal cells is affected in varying degree by different types of physical disturbance, and that they are not always equally permeable to all elements entering into the composition of the blood.

The Optical Activity of Cerebrospinal Fluid in Suppurative Meningitis, and Its Lactic Acid, Sugar, and Chloride Content

“…per liter. Wilcox, Lyttle and Hearn (11) find a mean concentration of about 109 for tuberculous meningitis, and report the blood chlorides also lowered though not to so great an extent. Linder and Carmichael (49), however, find that the ratio of cerebrospinal fluid chloride to blood chloride is unaltered in meningitis and conclude that the fall of chloride concentration in the cerebrospinal fluid in meningitis is dependent on a similar fall in the chloride concentration of the serum.…”

“…per 100 cc. (4)(5)(6)(7)(8)(9)(10)(11)(12)(22)(23)(24)(25). The reducing substance of cerebrospinal fluid has been found lower than that of blood.…”

“…The ratio has been reported as from 0.40 to 0.81 where fluid and blood have been obtained at approximately the same time (11)(12)(13)24). It has been reported that the reducing substance of cerebrospinal fluid varies with that of blood (11)(12)(13)(14)(15)(16)25), rising after meals (12)(13), falling after insulin (26), and maintaining a high level in diabetes and other conditions attended with hyperglycemia (14,23). On the other hand the range of the ratio given above indicates that the correlation is subject to considerable variation.…”